The submandibular gland is one of three major paired salivary glands. Cancer developing within it is a rare form of head and neck cancer, representing less than five percent of all head and neck malignancies. It is the second most common site for salivary gland tumors, after the parotid gland. Understanding the anatomy, symptoms, and specific treatment modalities is important for anyone researching this uncommon diagnosis.
Gland Location and Cancer Prevalence
The submandibular glands are located beneath the lower jawbone (mandible) in the neck. They produce saliva, which aids in digestion, keeps the mouth moist, and provides protection against infections. Tumors arising in the submandibular gland are more frequently malignant compared to those in the largest gland, the parotid.
Submandibular gland tumors account for about 10 to 15 percent of all major salivary gland malignancies. Common types include mucoepidermoid carcinoma and adenoid cystic carcinoma, with the latter often exhibiting a tendency to spread along nerves.
Recognizing Early Warning Signs
The most common initial indication of submandibular gland cancer is a lump or swelling beneath the jaw or in the upper neck. This mass is often painless, which can delay seeking medical attention. Any persistent lump warrants a medical evaluation.
Symptoms can arise when the tumor presses on or invades nearby nerves. This may cause persistent pain or discomfort in the face, jaw, or neck. Signs of nerve involvement include numbness or noticeable weakness, such as drooping on one side of the face.
As the tumor grows, it may interfere with functions like opening the mouth fully or swallowing (dysphagia). Rapid enlargement or fixation of the mass to the overlying skin are concerning signs. Though non-cancerous conditions can cause these symptoms, they require professional examination.
Confirmatory Diagnosis and Staging
Diagnosis begins with a physical examination where the doctor inspects the salivary glands and neck for masses, assessing their size and mobility. Imaging techniques are then used to visualize the tumor and determine its extent. A computed tomography (CT) scan or magnetic resonance imaging (MRI) provides detailed pictures and shows if the cancer has spread to nearby tissues or lymph nodes.
A positron emission tomography (PET) scan may check for metastasis to distant organs. Confirmation of the cancer type requires a biopsy, often a Fine Needle Aspiration (FNA), which collects a sample of cells and fluid. A pathologist examines this sample to identify the presence and type of malignant cells.
The extent of the cancer is determined through staging using the TNM classification system. This system assesses the primary Tumor size, spread to regional lymph Nodes, and distant Metastasis. This staging information, combined with the tumor’s grade (which indicates how quickly the cells are likely to grow), guides the oncology team in planning treatment.
Overview of Treatment Strategies
Treatment primarily centers on surgical removal of the tumor and the gland itself (submandibular gland excision). The goal is to achieve clear margins, meaning no cancer cells are found at the edges of the removed tissue. If the cancer has spread to the lymph nodes, a neck dissection may be performed simultaneously to remove involved nodes.
A significant consideration during surgery is the proximity of the tumor to important nerves, such as the marginal mandibular branch of the facial nerve. Surgeons strive to spare these nerves. However, if a nerve is directly involved or encased by the tumor, its removal may be necessary for complete cancer eradication, potentially resulting in long-term side effects like facial weakness or numbness.
Radiation therapy is frequently used after surgery, especially for high-grade tumors, spread to lymph nodes, or incomplete tumor removal. This adjuvant treatment targets remaining microscopic cancer cells to reduce recurrence. Chemotherapy is generally reserved for advanced stages, such as metastasis to distant sites or for palliative care, as these tumors often respond poorly to chemotherapy alone.